get_phys_pages, get_avphys_pages - get total and available physical page counts
#include <sys/sysinfo.h>
long int get_phys_pages(void);
long int get_avphys_pages(void);
The function
get_phys_pages() returns the total number of physical pages
of memory available on the system.
The function
get_avphys_pages() returns the number of currently available
physical pages of memory on the system.
On success, these functions return a nonnegative value as given in DESCRIPTION.
On failure, they return -1 and set
errno to indicate the cause of the
error.
- ENOSYS
- The system could not provide the required information (possibly because
the /proc filesystem was not mounted).
These functions are GNU extensions.
These functions obtain the required information by scanning the
MemTotal
and
MemFree fields of
/proc/meminfo.
The following
sysconf(3) calls provide a portable means of obtaining the
same information as the functions described on this page.
total_pages = sysconf(_SC_PHYS_PAGES); /* total pages */
avl_pages = sysconf(_SC_AVPHYS_PAGES); /* available pages */
The following example shows how
get_phys_pages() and
get_avphys_pages() can be used.
#include <stdio.h>
#include <stdlib.h>
#include <sys/sysinfo.h>
int
main(int argc, char *argv[])
{
printf("This system has %ld pages of physical memory and "
"%ld pages of physical memory available.\n",
get_phys_pages(), get_avphys_pages());
exit(EXIT_SUCCESS);
}
sysconf(3)